The document discusses the 5G core network, focusing on its characteristics, deployment flavors, and the necessary standards from 3GPP and ETSI. Key features include network slicing, cloud deployment enablers, and the differentiation between user and control planes. It emphasizes the need for standards for cross-domain orchestration and the role of APIs in the evolution towards a truly converged, cloud-native architecture.

1. 5G Core Network
and the Cloud
Sridhar Bhaskaran • 13.12.2017
A Standards Perspective

2. Agenda
5G Requirements
Standards - Who is Doing What?
3GPP Standards
● Flavors of 5G Deployment
● Use Cases Driving the Need For a New
5G Core Network
● 5G Core Network Overview
● 5G Core Network Features
● Enablers for Cloud Deployment

3. 5G Requirements (from NGMN)

4. 5G Use Case Category Definition (NGMN)

5. Standards - Who is Doing What?
● Specification of a New Radio Technology, Spectrum, Waveforms etc - 3GPP RAN (RAN1, RAN2, RAN3, RAN4 and
RAN5)
● Specification of System requirements, architecture, management and security - 3GPP SA (SA1, SA2, SA3 and SA5)
● Specification of core network protocols - 3GPP CT (CT1, CT3 and CT4)
● Architecture for Multi Access Edge Computing - ETSI MEC
● Architecture, Framework and APIs for Network Function Virtualization - ETSI NFV
● Other alternative Radio Technologies
○ IEEE 802.11ax - WLAN
○ LoRA for LPWAN (IoT)

6. 3GPP Standards
(5G Core Network)

7. Flavors of 5G Deployment - Option 3
Reference: 3GPP RAN Plenary Document RP-161266

8. Flavors of 5G Deployment - Option 7
Reference: 3GPP RAN Plenary Document RP-161266

9. Flavors of 5G Deployment - Options 2
Standalone NR
Reference: 3GPP RAN Plenary Document RP-161266

10. Use Cases Driving New 5G CN
● Diverse use cases - one network cant fit all ⇒ Network Slicing.
○ Independent deployment and management of each slice
○ Ability to own and manage a slice from a different administrative domain (e.g 3rd party enterprise)
○ Same application but provided by different enterprises (e.g vending machines from Coke and Pepsi)
○ Support for vertical market deployments
● Plug and play deployment of new features ⇒ Network Interactions via APIs ⇒ Service Based Architecture.
● Control Plane - User Plane separation from day 1 ⇒ Enabling SDN - centralized CP/distributed UP.
● Application influence on traffic steering.
● Common authentication framework for any access (3GPP, WLAN, Wireline). Common core for any access (3GPP, WLAN, Wireline) ⇒ True
fixed-mobile convergence.
● Support for Ethernet and Unstructured PDU types allowing deployment of LAN services over 3GPP radio.
● Support for Edge Computing ⇒ Local Area Data Network (LADN), Uplink Classifiers and Branching Points with Multihomed IPv6.
● Reduced signalling between UE and Core Network for IDLE-ACTIVE state transition + Energy efficient state handling at UE ⇒ RRC Inactive.
● Architectural Enablers for Virtualized / Cloud based Deployments ⇒ Support for stateless NFs.

11. 5G Core Network Architecture Overview
PGW
MME
SGW
HSS
PCRF AAA
ePDG
SCEF
Untrusted non 3GPP
Access (e.g Public WiFI)
GTP
Diameter
● Interfaces exposed as APIs on control plane
● Common control plane protocol (HTTP 2.0 over TCP)
● Network function service registry - NRF
LTE - Evolved Packet Core (EPC) 5G Core Network (5GC)
IKEv2

12. 5G Core Network Features - Network Slicing
UE RAN MME SGW
PGW
(APN1)
PGW
(APN2)
PGW
(APN3)
● 1 UE - connect to one Dedicated Core Network (DCN)
● 1 DCN can support multiple applications (APN)
● Same application support in multiple DCNs require repeated
configurations for same APN but different DCN in DNS
UE RAN AMF
SMF1
SMF2
SMF3
UPF1 DN-1
UPF2 DN-2
UPF3 DN-3
● 1 UE - can connect to multiple core network slices
● Each slice identified by an S-NSSAI
● AMF is common to all slices UE uses
● SMFs specific to each slice
● SMFs selected via NRF specific to the slice (S-NSSAI)
● NRFs + SMFs can be in different administrative domain from AMF
● SMFs select UPF
● Traffic routing of each slice is independent and isolated
● RAN supports slicing at the radio
● Network Slice Selection Policies provided to UE to
select a slice for a given application
LTE - Evolved Packet Core (EPC) 5G Core Network (5GC)

13. 5G Core Network Features - LADN (Multi
Access Edge Computing)
Registration Area
LADN Service
Area1
LADN Service
Area2
UPF
Local
Area DN
● AMF provides the list
of LADNs available in
a Registration Area
during UE
registration to the
network
● UE activates
sessions towards the
LADN when entering
the service area

14. Architectural Enablers for Cloud Deployment
● Storage of Network Function and session state in a unstructured data storage function (UDSF).
○ Allows session state to be separated from signalling thus enabling stateless NFs
● From protocol based signalling ⇒ API based core network signaling interaction.
○ Allows new features to be developed by reusing APIs
○ Direct interaction with needed NF via API
○ API and service discovery via NRF
● Ability to change the TNL (Transport Network Layer) address to UE session state binding anytime.

15. Challenges in Cloud Deployment
● Network slicing involving parts of slices spanning across administrative boundaries may
require multi-domain orchestration and resource co-ordination.
● Multi-domain orchestration is an open research area.
● No standard APIs yet for cross cloud federation.
● Once resources are instantiated and VNFs are onboarded - communication between VNFs
spanning across administrative boundaries will be through standardized 3GPP service
based interfaces.
● 3GPP SA5 defining information model for network slicing - concept of Network Slice
Subnet (e.g Transport network could be a subnet).
○ 3GPP TR 28.801 and TS 28.530
● A standard resource model leading to standard API will be a step in the right direction
(atleast for cross domain orchestration for slicing)

16. 3GPP SA5 Slice Management Model

17. 3GPP 5G Core Network Specifications
● 5G System Requirements - TS 22.261
● 5G System Architecture - TS 23.501
● 5G System Procedures and Call Flows - TS 23.502
● 5G Security - TS 33.501
● 5G Network Slice Management - TS 28.530
● Latest specifications to be available after Dec 20-22, 2017 SA Plenary at Lisbon
● http://www.3gpp.org/ftp/Specs/archive/23_series/
● http://www.3gpp.org/ftp/Specs/archive/22_series/

18. 3GPP 5G Timeline

19. 3GPP Release 16 and Beyond
● Support for massive IoT - core network enhancements to support cellular IoT features in 5G
● Support for Ultra Reliable and Low Latency Communication (URLLC) - new QoS characteristics,
enhanced UPF placement logic, Enablers for ultra reliability
● Wireless Wireline Convergence
● Support for Enhanced Network Automation using Analytics
● Multicast and Broadcast support over 5G
● 5G LAN

20. Summary
1. 5G Core Network is a Paradigm
Shift
2. First truly cloud native
architecture
3. API based - Easy 3rd party
application integration
4. First truly converged core for all
access
5. Diverse use case support

21. Thank You